1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 /*
27 *
28 * (C) Copyright IBM Corp. 2003 - All Rights Reserved
29 */
30
31 package sun.font;
32
33 import sun.font.GlyphLayout.*;
34 import java.awt.geom.Point2D;
35 import java.lang.ref.SoftReference;
36 import java.util.HashMap;
37 import java.util.Locale;
38 import java.util.concurrent.ConcurrentHashMap;
39
40 /*
41 * different ways to do this
42 * 1) each physical font2d keeps a hashtable mapping scripts to layout
43 * engines, we query and fill this cache.
44 * 2) we keep a mapping independent of font using the key Most likely
45 * few fonts will be used, so option 2 seems better
46 *
47 * Once we know which engine to use for a font, we always know, so we
48 * shouldn't have to recheck each time we do layout. So the cache is
49 * ok.
50 *
51 * Should we reuse engines? We could instantiate an engine for each
52 * font/script pair. The engine would hold onto the table(s) from the
53 * font that it needs. If we have multiple threads using the same
54 * engine, we still need to keep the state separate, so the native
55 * engines would still need to be allocated for each call, since they
56 * keep their state in themselves. If they used the passed-in GVData
57 * arrays directly (with some checks for space) then since each GVData
58 * is different per thread, we could reuse the layout engines. This
59 * still requires a separate layout engine per font, because of the
60 * table state in the engine. If we pushed that out too and passed it
61 * in with the native call as well, we'd be ok if the layout engines
62 * keep all their process state on the stack, but I don't know if this
63 * is true. Then we'd basically just be down to an engine index which
64 * we pass into native and then invoke the engine code (now a
65 * procedure call, not an object invocation) based on a switch on the
66 * index. There would be only half a dozen engine objects then, not
67 * potentially half a dozen per font. But we'd have to stack-allocate
68 * some state that included the pointer to the required font tables.
69 *
70 * Seems for now that the way to do things is to come in with a
71 * selector and the font. The selector indicates which engine to use,
72 * the engine is stack allocated and initialized with the required
73 * font tables (the selector indicates which). Then layout is called,
74 * the contents are copied (or not), and the stack is destroyed on
75 * exit. So the association is between the font/script (layout engine
76 * desc) and and one of a few permanent engine objects, which are
77 * handed the key when they need to process something. In the native
78 * case, the engine holds an index, and just passes it together with
79 * the key info down to native. Some default cases are the 'default
80 * layout' case that just runs the c2gmapper, this stays in java and
81 * just uses the mapper from the font/strike. Another default case
82 * might be the unicode arabic shaper, since this doesn't care about
83 * the font (or script or lang?) it wouldn't need to extract this
84 * data. It could be (yikes) ported back to java even to avoid
85 * upcalls to check if the font supports a particular unicode
86 * character.
87 *
88 * I'd expect that the majority of scripts use the default mapper for
89 * a particular font. Loading the hastable with 40 or so keys 30+ of
90 * which all map to the same object is unfortunate. It might be worth
91 * instead having a per-font list of 'scripts with non-default
92 * engines', e.g. the factory has a hashtable mapping fonts to 'script
93 * lists' (the factory has this since the design potentially has other
94 * factories, though I admit there's no client for this yet and no
95 * public api) and then the script list is queried for the script in
96 * question. it can be preloaded at creation time with all the
97 * scripts that don't have default engines-- either a list or a hash
98 * table, so a null return from the table means 'default' and not 'i
99 * don't know yet'.
100 *
101 * On the other hand, in most all cases the number of unique
102 * script/font combinations will be small, so a flat hashtable should
103 * suffice.
104 * */
105 public final class SunLayoutEngine implements LayoutEngine, LayoutEngineFactory {
106 private static native void initGVIDs();
107 static {
108 FontManagerNativeLibrary.load();
109 initGVIDs();
110 }
111
112 private LayoutEngineKey key;
113
114 private static LayoutEngineFactory instance;
115
116 public static LayoutEngineFactory instance() {
117 if (instance == null) {
118 instance = new SunLayoutEngine();
119 }
120 return instance;
121 }
122
123 private SunLayoutEngine() {
124 // actually a factory, key is null so layout cannot be called on it
125 }
126
127 public LayoutEngine getEngine(Font2D font, int script, int lang) {
128 return getEngine(new LayoutEngineKey(font, script, lang));
129 }
130
131 // !!! don't need this unless we have more than one sun layout engine...
132 public LayoutEngine getEngine(LayoutEngineKey key) {
133 // Using ConcurrentHashMap instead of HashMap to resolve 7027300
134 ConcurrentHashMap cache = (ConcurrentHashMap)cacheref.get();
135 if (cache == null) {
136 cache = new ConcurrentHashMap();
137 cacheref = new SoftReference(cache);
138 }
139
140 LayoutEngine e = (LayoutEngine)cache.get(key);
141 if (e == null) {
142 e = new SunLayoutEngine(key.copy());
143 cache.put(key, e);
144 }
145 return e;
146 }
147 private SoftReference cacheref = new SoftReference(null);
148
149 private SunLayoutEngine(LayoutEngineKey key) {
150 this.key = key;
151 }
152
153 public void layout(FontStrikeDesc desc, float[] mat, int gmask,
154 int baseIndex, TextRecord tr, int typo_flags,
155 Point2D.Float pt, GVData data) {
156 Font2D font = key.font();
157 FontStrike strike = font.getStrike(desc);
158 long layoutTables = 0;
159 if (font instanceof TrueTypeFont) {
160 layoutTables = ((TrueTypeFont) font).getLayoutTableCache();
161 }
162 nativeLayout(font, strike, mat, gmask, baseIndex,
163 tr.text, tr.start, tr.limit, tr.min, tr.max,
164 key.script(), key.lang(), typo_flags, pt, data,
165 font.getUnitsPerEm(), layoutTables);
166 }
167
168 private static native void
169 nativeLayout(Font2D font, FontStrike strike, float[] mat, int gmask,
170 int baseIndex, char[] chars, int offset, int limit,
171 int min, int max, int script, int lang, int typo_flags,
172 Point2D.Float pt, GVData data, long upem, long layoutTables);
173 }